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vue项目中常见的三种文件类型在线预览实现(pdf/word/excel表格)

时间：2022-06-08 09:20:14 | 栏目：vue | 点击：次

前言

之前做PDF预览一直用的pdf.js，这次没有太多附加需求比较简单简，所以决定用vue-pdf这个组件，虽然说它没有原生那样强大，但已经满足常用的需求了，重要是这个组件使用简单。顺便也把word文件和excel表格预览也整理了下，接下来我们直接进入正题！

一、预览word文件

1.安装 npm 依赖

npm i docx-preview@0.1.4
npm i jszip

2.预览在线地址文件

<template>
  <div class="home">
    <div ref="file"></div>
  </div>
</template>

<script>
import axios from 'axios'
const docx = require('docx-preview');
window.JSZip = require('jszip')
export default {
  mounted(){
    axios({
      method: 'get',
      responseType: 'blob', // 设置响应文件格式
      url: '/docx',
    }).then(({data}) => {
      docx.renderAsync(data,this.$refs.file) // 渲染到页面预览
    })
  }
}
</script>

3.预览本地文件

<template>
  <div class="my-component" ref="preview">
    <input type="file" @change="preview" ref="file">
  </div>
</template>
<script>
const docx = require('docx-preview');
window.JSZip = require('jszip')
export default {
  methods:{
    preview(e){
      docx.renderAsync(this.$refs.file.files[0],this.$refs.preview) // 渲染到页面预览
    }
  }
};
</script>
<style lang="less" scoped>
.my-component{
  width: 100%;
  height: 90vh;
  border: 1px solid #000;
}
</style>

二、预览excel表格

1.安装依赖

npm i xlsx

2.预览在线表格

<template>
  <div class="home">
    <div v-html="tableau"></div>
  </div>
</template>

<script>
import axios from 'axios'
import XLSX from "xlsx";
export default {
  data(){
    return {
      tableau: null,
    }
  },
  mounted(){
     axios.get('/xlsx',{
       responseType: "arraybuffer", // 设置响应体类型为arraybuffer
     }).then(({data})=> {
       let workbook = XLSX.read(new Uint8Array(data), {type:"array"}); // 解析数据
       var worksheet = workbook.Sheets[workbook.SheetNames[0]]; // workbook.SheetNames 下存的是该文件每个工作表名字,这里取出第一个工作表
       this.tableau = XLSX.utils.sheet_to_html(worksheet); // 渲染
     })
  }
}
</script>

三、pdf预览

1.安装依赖vue-pdf

npm install --save vue-pdf

2.在需要的页面注册

<script> 
import PDF from 'vue-pdf'
export default {
  components:{
      PDF,
  },
  data(){
      return {

      }
  }
</script>

3.使用

一般预览pdf时都是很多页的，为了提升性能可以做个分页。page: 当前显示的页数，比如第一页page=1；rotate ： 旋转角度，比如0就是不旋转，+90，-90 就是水平旋转。progress ：当前页面的加载进度，范围是0-1 ，等于1的时候代表当前页已经完全加载完成了。page-loaded ：页面加载成功的回调函数，不咋能用到。num-pages ：总页数；error ：加载错误的回调link-clicked：单机pdf内的链接会触发。print 这个是打印函数。（注意：谷歌浏览器预览时会出现乱码，这个问题是因为你pdf中使用了自定义字体导致的。若要解决须替换node_modules/vue-pdf/src/pdfjsWrapper.js，替换的pdfjsWrapper.js我放在文章最后）

    <!-- 预览PDF -->
    <el-dialog v-dialogDrag  :visible.sync="previewDialog">
      <template>
        <div>
          <div class="tools">
            <el-button :theme="'default'" type="submit" :title="'上一页'" @click.stop="prePage" class="mr10"> 上一页</el-button>
            <el-button :theme="'default'" type="submit" :title="'下一页'" @click.stop="nextPage" class="mr10"> 下一页</el-button>
            <div class="page">{{pageNum}}/{{pageTotalNum}} </div>
            <el-button :theme="'default'" type="submit" :title="'顺时针旋转'" @click.stop="clock" class="mr10"> 顺时针旋转</el-button>
            <el-button :theme="'default'" type="submit" :title="'逆时针旋转'" @click.stop="counterClock" class="mr10"> 逆时针旋转</el-button>
            <el-button :theme="'default'" type="submit" :title="'打印'" @click.stop="pdfPrintAll" class="mr10"> 打印</el-button>
          </div>
          <pdf ref="pdf" :src="url" :page="pageNum" :rotate="pageRotate" @progress="loadedRatio = $event" @page-loaded="pageLoaded($event)" 
            @num-pages="pageTotalNum=$event" @error="pdfError($event)"  @link-clicked="page = $event"></pdf>
        </div>
      </template>
    </el-dialog>
<script> 
import PDF from 'vue-pdf'
export default {
  components:{
      PDF,
  },
  data(){
      return {
      	previewDialog:false,
      	url: "http://storage.xuetangx.com/public_assets/xuetangx/PDF/PlayerAPI_v1.0.6.pdf",
      	pageNum: 1,
      	pageTotalNum: 1,
      	pageRotate: 0,
      	// 加载进度
      	loadedRatio: 0,
      	curPageNum: 0,
      },
      methods:{
    /**
     * 预览PDF
     */
    previewPDF(row,index) {
      this.previewDialog = true;
      console.log("", row,index);
      
    },
    // 上一页函数，
    prePage() {
      var page = this.pageNum
      page = page > 1 ? page - 1 : this.pageTotalNum
      this.pageNum = page
    },
    // 下一页函数
    nextPage() {
      var page = this.pageNum
      page = page < this.pageTotalNum ? page + 1 : 1
      this.pageNum = page
    },
    // 页面顺时针翻转90度。
    clock() {
      this.pageRotate += 90
    },
    // 页面逆时针翻转90度。
    counterClock() {
      this.pageRotate -= 90
    },
    // 页面加载回调函数，其中e为当前页数
    pageLoaded(e) {
      this.curPageNum = e
    },
    // 错误时回调函数。
    pdfError(error) {
      console.error(error)
    },
    // 打印全部
    pdfPrintAll() {
      /**
       * 打印界面字符乱码是因为你pdf中使用了自定义字体导致的,谷歌浏览器打印的时候预览界面真的变成了真·方块字 ,解决方案如下：
       * 用文章最后的pdfjsWrapper.js在替换掉node_modules/vue-pdf/src/pdfjsWrapper.js
       */
      console.log("打印");
      this.$refs.pdf.print()
    },

	 },
  }
</script>

4.加载本地pdf文件

如果需要加载本地pdf文件（不需要则不用配置），需要我们做一下本地配置flie-loader才行，否则webpack无法编译pdf类型的文件，配置方法也很简单，在项目根目录找到vue.config.js文件（若没有则在根目录下新建一个vue.config.js）。之后再url:require("…/assets/xxx.pdf")就没有任何问题了，注意，vue-pdf src接收的是string对象，如果直接传url这里报错了，需要传url.default一下。

先安装file-loader

npm install --save file-loader

然后在vue.config.js中加入以下内容：

module.exports = {
    chainWebpack: config => {
        const fileRule = config.module.rule('file')
        fileRule.uses.clear()
        fileRule
            .test(/\.pdf|ico$/)
            .use('file-loader')
            .loader('file-loader')
            .options({
                limit: 10000,
            })
    },
    publicPath: './'
}

5.解决pdf使用自定义字体预览和打印乱码问题：pdfjsWrapper.js

import { PDFLinkService } from 'pdfjs-dist/es5/web/pdf_viewer';
var pendingOperation = Promise.resolve();
export default function(PDFJS) {
	function isPDFDocumentLoadingTask(obj) {
		return typeof(obj) === 'object' && obj !== null && obj.__PDFDocumentLoadingTask === true;
		// or: return obj.constructor.name === 'PDFDocumentLoadingTask';
	}

	function createLoadingTask(src, options) {
		var source;
		if ( typeof(src) === 'string' )
			source = { url: src };
		else if ( src instanceof Uint8Array )
			source = { data: src };
		else if ( typeof(src) === 'object' && src !== null )
			source = Object.assign({}, src);
		else
			throw new TypeError('invalid src type');

		// source.verbosity = PDFJS.VerbosityLevel.INFOS;
		// source.pdfBug = true;
		// source.stopAtErrors = true;

		if ( options && options.withCredentials )
			source.withCredentials = options.withCredentials;

		var loadingTask = PDFJS.getDocument(source);
		loadingTask.__PDFDocumentLoadingTask = true; // since PDFDocumentLoadingTask is not public

		if ( options && options.onPassword )
			loadingTask.onPassword = options.onPassword;

		if ( options && options.onProgress )
			loadingTask.onProgress = options.onProgress;

		return loadingTask;
	}


	function PDFJSWrapper(canvasElt, annotationLayerElt, emitEvent) {

		var pdfDoc = null;
		var pdfPage = null;
		var pdfRender = null;
		var canceling = false;

		canvasElt.getContext('2d').save();

		function clearCanvas() {

			canvasElt.getContext('2d').clearRect(0, 0, canvasElt.width, canvasElt.height);
		}

		function clearAnnotations() {

			while ( annotationLayerElt.firstChild )
				annotationLayerElt.removeChild(annotationLayerElt.firstChild);
		}

		this.destroy = function() {

			if ( pdfDoc === null )
				return;

			// Aborts all network requests and destroys worker.
			pendingOperation = pdfDoc.destroy();
			pdfDoc = null;
		}

		this.getResolutionScale = function() {

			return canvasElt.offsetWidth / canvasElt.width;
		}

		this.printPage = function(dpi, pageNumberOnly) {

			if ( pdfPage === null )
				return;

			// 1in == 72pt
			// 1in == 96px
			var PRINT_RESOLUTION = dpi === undefined ? 150 : dpi;
			var PRINT_UNITS = PRINT_RESOLUTION / 72.0;
			var CSS_UNITS = 96.0 / 72.0;

			var printContainerElement = document.createElement('div');
			printContainerElement.setAttribute('id', 'print-container')

			function removePrintContainer() {
				printContainerElement.parentNode.removeChild(printContainerElement);
			}

			new Promise(function(resolve, reject) {
				printContainerElement.frameBorder = '0';
				printContainerElement.scrolling = 'no';
				printContainerElement.width = '0px;'
				printContainerElement.height = '0px;'
				printContainerElement.style.cssText = 'position: absolute; top: 0; left: 0';

				window.document.body.appendChild(printContainerElement);
				resolve(window)
			})
			.then(function(win) {

				win.document.title = '';

				return pdfDoc.getPage(1)
				.then(function(page) {

					var viewport = page.getViewport({ scale: 1 });
					printContainerElement.appendChild(win.document.createElement('style')).textContent =
					'@supports ((size:A4) and (size:1pt 1pt)) {' +
							'@page { margin: 1pt; size: ' + ((viewport.width * PRINT_UNITS) / CSS_UNITS) + 'pt ' + ((viewport.height * PRINT_UNITS) / CSS_UNITS) + 'pt; }' +
						'}' +
						'#print-canvas { display: none }' +

						'@media print {' +
							'body { margin: 0 }' +
							'#print-canvas { page-break-before: avoid; page-break-after: always; page-break-inside: avoid; display: block }' +
							'body > *:not(#print-container) { display: none; }' +
							'}'+

						'@media screen {' +
							'body { margin: 0 }' +
						'}'
					return win;
				})
			})
			.then(function(win) {

				var allPages = [];

				for ( var pageNumber = 1; pageNumber <= pdfDoc.numPages; ++pageNumber ) {

					if ( pageNumberOnly !== undefined && pageNumberOnly.indexOf(pageNumber) === -1 )
						continue;

					allPages.push(
						pdfDoc.getPage(pageNumber)
						.then(function(page) {

							var viewport = page.getViewport({ scale: 1 });

							var printCanvasElt = printContainerElement.appendChild(win.document.createElement('canvas'));
							printCanvasElt.setAttribute('id', 'print-canvas')
							printCanvasElt.width = (viewport.width * PRINT_UNITS);
							printCanvasElt.height = (viewport.height * PRINT_UNITS);

							return page.render({
								canvasContext: printCanvasElt.getContext('2d'),
								transform: [ // Additional transform, applied just before viewport transform.
									PRINT_UNITS, 0, 0,
									PRINT_UNITS, 0, 0
								],
								viewport: viewport,
								intent: 'print'
							}).promise;
						})
					);
				}

				Promise.all(allPages)
				.then(function() {

					win.focus(); // Required for IE
					if (win.document.queryCommandSupported('print')) {
						win.document.execCommand('print', false, null);
					} else {
						win.print();
					}
					removePrintContainer();
				})
				.catch(function(err) {
					removePrintContainer();
					emitEvent('error', err);
				})
			})
		}

		this.renderPage = function(rotate) {
			if ( pdfRender !== null ) {

				if ( canceling )
					return;
				canceling = true;
				pdfRender.cancel().catch(function(err) {
					emitEvent('error', err);
				});
				return;
			}

			if ( pdfPage === null )
				return;

			var pageRotate = (pdfPage.rotate === undefined ? 0 : pdfPage.rotate) + (rotate === undefined ? 0 : rotate);

			var scale = canvasElt.offsetWidth / pdfPage.getViewport({ scale: 1 }).width * (window.devicePixelRatio || 1);
			var viewport = pdfPage.getViewport({ scale: scale, rotation:pageRotate });

			emitEvent('page-size', viewport.width, viewport.height, scale);

			canvasElt.width = viewport.width;
			canvasElt.height = viewport.height;

			pdfRender = pdfPage.render({
				canvasContext: canvasElt.getContext('2d'),
				viewport: viewport
			});

			annotationLayerElt.style.visibility = 'hidden';
			clearAnnotations();

			var viewer = {
				scrollPageIntoView: function(params) {
					emitEvent('link-clicked', params.pageNumber)
				},
			};

			var linkService = new PDFLinkService();
			linkService.setDocument(pdfDoc);
			linkService.setViewer(viewer);

			pendingOperation = pendingOperation.then(function() {

				var getAnnotationsOperation =
				pdfPage.getAnnotations({ intent: 'display' })
				.then(function(annotations) {

					PDFJS.AnnotationLayer.render({
						viewport: viewport.clone({ dontFlip: true }),
						div: annotationLayerElt,
						annotations: annotations,
						page: pdfPage,
						linkService: linkService,
						renderInteractiveForms: false
					});
				});

				var pdfRenderOperation =
				pdfRender.promise
				.then(function() {

					annotationLayerElt.style.visibility = '';
					canceling = false;
					pdfRender = null;
				})
				.catch(function(err) {

					pdfRender = null;
					if ( err instanceof PDFJS.RenderingCancelledException ) {

						canceling = false;
						this.renderPage(rotate);
						return;
					}
					emitEvent('error', err);
				}.bind(this))

				return Promise.all([getAnnotationsOperation, pdfRenderOperation]);
			}.bind(this));
		}


		this.forEachPage = function(pageCallback) {

			var numPages = pdfDoc.numPages;

			(function next(pageNum) {

				pdfDoc.getPage(pageNum)
				.then(pageCallback)
				.then(function() {

					if ( ++pageNum <= numPages )
						next(pageNum);
				})
			})(1);
		}


		this.loadPage = function(pageNumber, rotate) {

			pdfPage = null;

			if ( pdfDoc === null )
				return;

			pendingOperation = pendingOperation.then(function() {

				return pdfDoc.getPage(pageNumber);
			})
			.then(function(page) {

				pdfPage = page;
				this.renderPage(rotate);
				emitEvent('page-loaded', page.pageNumber);
			}.bind(this))
			.catch(function(err) {

				clearCanvas();
				clearAnnotations();
				emitEvent('error', err);
			});
		}

		this.loadDocument = function(src) {

			pdfDoc = null;
			pdfPage = null;

			emitEvent('num-pages', undefined);

			if ( !src ) {

				canvasElt.removeAttribute('width');
				canvasElt.removeAttribute('height');
				clearAnnotations();
				return;
			}

			// wait for pending operation ends
			pendingOperation = pendingOperation.then(function() {

				var loadingTask;
				if ( isPDFDocumentLoadingTask(src) ) {

					if ( src.destroyed ) {

						emitEvent('error', new Error('loadingTask has been destroyed'));
						return
					}

					loadingTask = src;
				} else {

					loadingTask = createLoadingTask(src, {
						onPassword: function(updatePassword, reason) {

							var reasonStr;
							switch (reason) {
								case PDFJS.PasswordResponses.NEED_PASSWORD:
									reasonStr = 'NEED_PASSWORD';
									break;
								case PDFJS.PasswordResponses.INCORRECT_PASSWORD:
									reasonStr = 'INCORRECT_PASSWORD';
									break;
							}
							emitEvent('password', updatePassword, reasonStr);
						},
						onProgress: function(status) {

							var ratio = status.loaded / status.total;
							emitEvent('progress', Math.min(ratio, 1));
						}
					});
				}

				return loadingTask.promise;
			})
			.then(function(pdf) {

				pdfDoc = pdf;
				emitEvent('num-pages', pdf.numPages);
				emitEvent('loaded');
			})
			.catch(function(err) {

				clearCanvas();
				clearAnnotations();
				emitEvent('error', err);
			})
		}
		annotationLayerElt.style.transformOrigin = '0 0';
	}

	return {
		createLoadingTask: createLoadingTask,
		PDFJSWrapper: PDFJSWrapper,
	}
}

总结

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